Cita APA (7th ed.)

Gray, R. (1961). A history of the Southern Sudan, 1839-1889. Oxford University Press.

Cita Chicago (17th ed.)

Gray, Richard. A History of the Southern Sudan, 1839-1889. [London]: Oxford University Press, 1961.

Cita MLA (9th ed.)

Gray, Richard. A History of the Southern Sudan, 1839-1889. Oxford University Press, 1961.